-LRB- CNN -RRB- -- A 14-year-old autistic Michigan girl whose mother allegedly tried to poison her with carbon monoxide in a murder-suicide attempt is recovering well , authorities said Tuesday .

Isabelle Stapleton is `` awake '' and `` responding , '' according to Sara Swanson , Benzie County prosecuting attorney , after being in critical care for carbon monoxide poisoning following a grisly incident last week in which her mother allegedly attempted to take both of their lives .

`` Her condition has continued to improve every day '' since the weekend , Swanson said .

On the evening of September 3 , Kelli Stapleton and her daughter were transported to hospitals for treatment of carbon monoxide poisoning after police discovered them unconscious inside their family vehicle in a wooded area , according to Sgt. Malcolm Irwin of Michigan State Police .

Officers found the vehicle locked with two charcoal grills burning inside , emitting carbon monoxide and using up the oxygen , according to Irwin .

Matt Stapleton , Isabelle 's father , had called police earlier in the day because `` nobody had seen '' her or her mother `` all day , '' Irwin said .

Isabelle was transported to the critical care unit at DeVos Children 's Hospital in Grand Rapids , Michigan , where she remained until she opened her eyes over the weekend , Swanson said .

Kelli Stapleton was taken into custody last Wednesday after receiving doctor 's clearance . She was arraigned on Thursday and is charged with one count of attempted murder . She is being held without bail and is to appear in court on September 16 for a preliminary examination , according to Swanson .

In a preliminary examination , a judge rules on whether there is sufficient evidence to support the charges .

In her blog , titled `` The Status Woe , '' Kelli Stapleton complained of suffering from `` a severe case of battle fatigue '' on the day of the alleged murder-suicide attempt .

The blog is devoted to Isabelle and the post from September 3 mentions the issues surrounding her autism treatment .

Stapleton 's attorney , Anthony Cicchelli , had no comment .

The Center for Disease Control and Prevention says on its website that an estimated one in 88 children has been identified with an autism spectrum disorder , or ASD .

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Isabelle Stapleton , 14 , was found with her mother in a car with charcoal grills burning

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Authorities say the mother was trying to kill both the autistic girl and herself

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The mother had blogged that she was suffering `` a severe case of battle fatigue ''